int mdt_handle_idmap(struct tgt_session_info *tsi)
{
        struct ptlrpc_request   *req = tgt_ses_req(tsi);
        struct mdt_device       *mdt = mdt_exp2dev(req->rq_export);
        struct mdt_export_data *med;
        struct ptlrpc_user_desc *pud = req->rq_user_desc;
        struct md_identity *identity;
        __u32 opc;
        int rc = 0;
        ENTRY;

        if (!req->rq_export)
                RETURN(0);